1. Field of the Invention
This invention relates to a transparency storage book for holding a plurality of transparencies for projector use, more particularly to a loose-leaf sheet for a transparency storage book.
2. Description of the Related Art
Referring to FIG. 1, a conventional loose-leaf sheet 1 is shown to include a transparent pocket 11 with an upper opening 111, and a binding strip unit 12, which is formed with a plurality of binding holes 121. A transparency 13 is inserted into the pocket 11 through the opening 111. The sheet 1 suffers from the following disadvantages:
(1) When the transparency 13 is placed within the sheet 1, and when the sheet 1 is positioned in a loose-leaf book (not shown), patterns and/or words on the transparency 13 cannot be seen clearly. A thin paper sheet (not shown) is therefore inserted into the pocket 11 behind the transparency 13 to facilitate visual inspection of the transparencies in the book (not shown), thereby making the transparency 13 and the paper (not shown) difficult to be inserted into and removed from the pocket 11 due to the fact that static electricity occurs between any adjacent pair of the transparency 13, the paper sheet (not shown), and the pocket 11.
(2) When projected onto a screen (not shown) by a projector (not shown), the patterns and/or words on the transparency 13, which is enclosed within the pocket 11 with no paper sheet inserted into the pocket 11, cannot be seen clearly in view of the condition that the light-permeability of the pocket 11 is relatively low.
(3) Because the pocket 11 is made of polyester, which cannot absorb water, when moisture is left between the transparency 13 and the pocket 11, the patterns and/or words on the transparency 13 will be printed on the pocket 11 due to contact between the transparency 13 and the pocket 11, thereby resulting in reduced clarity.
(4) After the plastic pocket 11 is thrown away, it results in an environmental waste problem.
Referring to FIG. 2, another conventional loose-leaf sheet 2 is shown to include a pocket 21 that is formed with an opening 211, and a binding strip unit 22 that is formed with a plurality of binding holes 221. The sheet 2 is similar to the sheet 1 in construction except that the pocket 21 is made of a high-light-permeability material. Although the assembly of the pocket 21 and the transparency 23 can be placed directly onto a projector (not shown) so that patterns and/or words on the transparency 23 can be seen more clearly on a screen, the sheet 2 has the same disadvantages, when compared to that shown in FIG. 1.